The paper proposes a measure of financial fragility that is based on economic welfare in a general equilibrium model calibrated against UK data. The model comprises a household sector, three active heterogeneous banks, a central bank/regulator, incomplete markets, and endogenous default. We address the impact of monetary and regulatory policy, credit and capital shocks in the real and financial sectors and how the response of the economy to shocks relates to our measure of financial fragility. Finally we use panel VAR techniques to investigate the relationships between the factors that characterise financial fragility in our model, i.e. banks’ probabilities of default and banks’ profits – to a proxy of welfare.

Our purpose in this paper is to produce a tractable model which illuminates problems relating to individual bank behaviour and risk-taking, to possible contagious interrelationships between banks, and to the appropriate design of prudential requirements and incentives to limit excessive risk-taking. Our model is rich enough to include heterogenous agents (commercial banks and investors), endogenous default, and multiple commodity, and credit and deposit markets. Yet, it is simple enough to be effectively computable. Financial fragility emerges naturally as an equilibrium phenomenon. In our model a version of the liquidity trap can occur. Moreover, the Modigliani-Miller proposition fails either through frictions in the (nominal) financial system or through incentives, arising from the imposed capital requirements, for differential investment behaviour because of capital requirements. In addition, a non-trivial quantity theory of money is derived, liquidity and default premia co-determine interest rates, and both regulatory and monetary policies have non-neutral effects. The model also indicates how monetary policy may affect financial fragility, thus highlighting the trade-off between financial stability and economic efficiency.

The purpose of our work is to explore contagious financial crises. To this end, we use simplified, thus numerically solvable, versions of our general model [C.A.E. Goodhart, P. Sunirand, D.P. Tsomocos, A Model to Analyse Financial Fragility, Oxford Financial Research Centre Working Paper No. 2003fe13, 2003]. The model incorporates heterogeneous agents, banks and endogenous default, thus allowing various feedback and contagion channels to operate in equilibrium. Such a model leads to different results from those obtained when using a standard representative agent model. For example, there may be a trade-off between efficiency and financial stability, not only for regulatory policies, but also for monetary policy. Moreover, agents who have more investment opportunities can deal with negative shocks more effectively by transferring ‘negative externalities’ onto others

Goodhart, Charles, Sunirand, Pojanart and Tsomocos, Dimitrios
(2005)
A Risk Assessment Model for Banks.
Annals of Finance, 1 (2).
pp. 197-224.
Link to full text available through this repository.

Abstract

The objective of this paper is to propose a model to assess risk for banks. Its main innovation is to incorporate endogenous interaction between banks, recognising that the actual risk to which an individual bank is exposed also depends on its interaction with other banks and other private sector agents. To this end, we develop a two-period general equilibrium model with three active heterogeneous banks, incomplete markets, and endogenous default. The setting of three heterogeneous banks allows us to study not only interaction between any two individual banks, but also their interaction with the rest of the banks in the banking system. We show that the model is analytically tractable and can be calibrated against real UK banking data and therefore can be implemented as a risk assessment tool for financial regulators and central banks. We address the impact of monetary and regulatory policy as well as credit and capital shocks in the real and financial sectors.

The purpose of this paper is to create a financial fragility model for the Czech financial sector. We adapt the Goodhart-Tsomocos model which is based on general equilibrium with incomplete markets, money and default. The calibration of the model is based on publicly available data from the period 2003-2011. Finally, we perform comparative statics to show how the key variables of the model respond to possible events. The model can be used by government institutions to stress-test the banking sector, as well as by banking and other financial institutions to estimate the development of, inter alia, the default rates of their clients. The model also incorporates default of households and may be used, after further extension, in predicting households' default rates with respect to the behaviour of banks in consequence of changes in macroeconomic parameters of the environment.